The present invention relates to an apparatus for generating multi energy data from phase contrast imaging data. It is described to provide (210) phase contrast X-ray image data of a region of interest of an object. Attenuation X-ray image data of the region of interest of the object is also provided (220). A first basis data set is generated (230) from the phase contrast X-ray image data. A second basis data set is generated (240) from the phase contrast X-ray image data and the attenuation X-ray image data.
